Monday, February 23, 2004
Copyright © Las Vegas Review-Journal

GROWING PAINS: New Thinking

Scientists learning adolescent brain develops more slowly than previously believed

Click image for enlargement. Photo Illustration by Jeff Scheid.

It happened to your grandparents. Then it happened to your parents. And, if you have adolescents, it's happening to you.

That once achingly sweet toddler who became a winsome child charming strangers in checkout lines is torturing you, his parents, with teenaged apathy and angst.

The kid you were convinced was the next Albert Einstein has been replaced by what looks like an underage adult but acts like a mumbling ogre whose brain seems to have short-circuited. He drives a car and holds a job, plans to vote soon and maybe join the military. But he sleeps in class -- when he goes -- drag races on city streets, rides grocery carts down embankments or re-enacts other stunts from MTV's "Jackass." He's moody, makes decisions a 9-year-old might find questionable and sometimes acts like he should be wearing Pampers instead of Paper jeans.

While society has long passed off such teen characteristics as hormone-induced, a growing body of research suggests its cause may be an immature brain. An adolescent brain, if you will.

Scientists had believed for years that the brain was almost structurally mature at about age 5. But several studies, using Magnetic Resonance Imaging, found that it continues to mature throughout adolescence into adulthood, especially in the frontal lobes.

That's meaningful and important, says University of California, Los Angeles neuroscientist Elizabeth Sowell, because the frontal lobes are the executive seat of the brain, the area that is responsible for decision-making, problem solving, planning and other functions. It controls behavior, too, helping to inhibit inappropriate responses. It also is the area responsible for personality.

And those are the things that can give adolescents a bad name, says Sowell, whose research at UCLA's Laboratory of Neuro Imaging focuses on the structure of the brain and how it changes in adolescence.

"The frontal lobes' job is to take information from all other areas of the brain and help you make decisions that are rational," says Lewis Etcoff, a local neuropsychologist who has treated children and adolescents in his private practice for 20 years. "Essentially kids are less able to think as rationally as adults because they're not biologically advanced enough."

During adolescence, generally 10 to 20 years old, the limbic system, or that part of the brain responsible for emotion, is more powerful because the frontal lobes aren't able to filter visceral responses, Etcoff explains. This makes adolescents more susceptible to peer pressure and more inclined toward instant gratification. That's why many adolescents become clumsy, impulsive, immature risk-takers who will do almost anything to fit in with the crowd, Etcoff says.

"The older you get the fewer risks you take," Etcoff explains. "With teens, they don't see beyond their nose. They're now oriented. They say, `Let's do it now, this is a blast, let's do it.' They actually act without thinking. Their brains aren't developed enough to think beyond `I shouldn't carry a gun, I shouldn't drink and drive.' "

While nobody needed research to know that teens are different from adults, the findings help by partially explaining the reasons why, Etcoff says. It also raises the issue of when teens should begin taking on adult responsibilities, such as driving.

"They're more dangerous by being teenagers, they can now start using drugs, can start having unprotected sex, they get driver's licenses," Etcoff says, adding that the research "makes a good argument for graduated driver's licenses."

Mike Males, a sociologist at the University of California, Santa Cruz and senior researcher for the Center on Juvenile and Criminal Justice, says current research findings overshadow previous research that showed teens can be much like adults when it comes to decision making and planning.

"This is very speculative, it's been way overextended by some researchers. We don't know enough," Males says. "There's no particular pattern that shows adolescents are any more peer driven or impulsive than adults. Everybody takes off the table the risks adults take. I think a general statement is that there are advantages to the adult brain and advantages to the child brain."

Etcoff and Sowell each agree the research is only the beginning of understanding normal adolescent development, adding that it doesn't begin to explain abnormal behavior or take into account adult behavior.

The research can't explain why adolescents carry guns to school and open fire on classmates or crash planes into buildings, as a 15-year-old did shortly after Sept. 11, 2001, Sowell says.

"There may be larger societal points we can address at some point but not now," Sowell says.